import java.util.Scanner;

//走方格的方案数
public class route {
    public static int num=0;

    public static  void result(int num1,int num2,int row,int line)
    {
        if(num1==row&&num2==line)
        {
            num++;
            return;
        }
        if(num1<=row)
        {
            int num3=num1+1;
            result(num3,num2,row,line);
        }
        if(num2<=line)
        {
            int num3=num2+1;
            result(num1,num3,row,line);
        }
    }


    public static void main(String[] args) {
        Scanner sc=new  Scanner(System.in);
        int row=sc.nextInt();
        int line= sc.nextInt();
        result(0,0,row,line);
        System.out.println(num);
    }
}
